Default: history logging is enabled. When
--no-connection is specified, history
logging is automatically disabled. When
--connect-if-online is specified, history
logging only works if a database connection is
successfully established during the backup.

--comments=STRING

Specify a comment string that describes or identifies the
backup. Surround multi-word comments with appropriate
quotation marks. The string is saved in a file
meta/comments.txt in the backup. For
example: --comments="Backup of HR data on
2010/12/10".

--comments-file=PATH

Specify path to a file containing comments describing the
backup. This file is saved as
meta/comments.txt in the backup. For
example:
--comments-file=/path/to/comments.txt.